UPDATE 1-Malaysia's Petronas appoints industry veteran as chairman

KUALA LUMPUR, Aug 1 (Reuters) - Malaysia has appointed Ahmad Nizam Salleh as the new chairman of state-owned oil company Petroliam Nasional Bhd (Petronas) effective immediately, the prime minister’s office said on Wednesday.

Ahmad Nizam has spent most of his 37-year career in the oil and gas industry at Petronas, the office said, and replaces Sidek Hassan.

Petronas announced in early July that Sidek had ended his tenure as chairman on June 30.

Wan Zulkiflee Wan Ariffin, who took over as CEO in April 2015, remains as president and chief executive of Petronas, the statement said.

Malaysian state-linked firms have seen a change of top officials since the new government led by returning premier Mahathir Mohamad took power following a shock election win in May. Mahathir has criticised the management of state-linked firms and promised structural reforms.

Malaysia’s sovereign wealth fund Khazanah Nasional has seen sweeping changes with the entire board offering to resign last week.

Mahathir was appointed chairman of the fund on Monday, and four new directors were named including Malaysia’s economics affairs minister Mohamed Azmin Ali.

Last Friday, state palm oil plantation agency Federal Land Development Authority (Felda) appointed Megat Zaharuddin Megat Mohd Nor, formerly the chairman at Malayan Banking Bhd (Maybank) , as its new chairman to replace Shahrir Samad. (Reporting by Emily Chow and Liz Lee Editing by Manolo Serapio Jr. and Susan Fenton)